"Facebook is calling the new product “add a link” and while it may seem small, there are two important but subtle elements to the update. The first is that Facebook is finally starting to flex its muscle a bit when it comes to search. Facebook has a ton of information about its users and the things they share and talk about — a company blog post claims its archive includes more than a trillion posts. Helping people find all that info has never been one of Facebook’s strengths, and this is another step toward shoring up that ability. [...]

The potentially more important element is that “add a link” helps keep people in the Facebook app. If you don’t need to go out and hunt down a link outside of Facebook, you may be more willing to stay and share. It’s one of the same reasons Facebook is now willing to host content from publishers like the New York Times and BuzzFeed. The longer you stay within the app and the more you share, the better it is for Facebook’s business."